1. Field of the Invention
This invention relates to a method and apparatus for affixing a plurality of surfaces to one another, using an adjustable attachment and more particularly to a method and apparatus affixing surfaces in a computing environment to one another using an adjustable attachments.
2. Description of Background
Large computing system environments are often comprised of a cage like frame or rack, with a plurality of insertable nodes that are plugged into this frame. The nodes often include a variety of electronic components, such as daughter cards, processors and other such components. The frame often consists of a plurality of vertically extending supports that interconnect two or more horizontal rails. Side and rear and/or front structural surfaces can also be optionally added to enhance structural rigidity or to accommodate the thermal interface subassemblies used to cool the computing system environment.
In order to insert the nodes containing electronic components are inserted into the frame, the frame is often provided with mating interconnects that receive these nodes. After they are plugged into their mating interconnects, the nodes are then fixed, latched or mounted into a position using a number mounting devices to prevent relative movement. Operational vibration and shock as some examples, make it a necessity that these assemblies are mounted to avoid a number of issues such as potential functional problems such as intermittent due to connection wear.
The ability to rigidly attach these nodes once they are plugged or placed into their mating interconnects and final position, becomes a function of the substructures node tolerance as well as the tolerance of the frame and the ability to rigidly span that tolerance with a sufficiently rigid member. It is undesirable to design mounting apparatus that delivers loading or stresses to the interconnect system as it not only affect the structural integrity of the computing environment and may potentially even lead to performance problems. Similarly, any design that leads to unbalanced loading of the frame and substructure is also undesirable for similar reasons.
A number of solutions are provided in the prior art to provide a viable mounting apparatus. These include a variety of designs implementing springs and other elastic means as part of their incorporated solution.
However, these solutions do not always provide the necessary mounting rigidity that can make the nodes immune to vibrations and shipping shock, among other things.
One particular challenge stems from tolerance buildup. In one measured case, where experimental data was collected, the implementation of prior art led to a case where the tolerance buildup was as much as 2.2 and there was a gap between the mounting bracket (of a node) and the frame (central electronic complex—CEC) caged frame on account of this tolerance buildup. The torque value in this instance was also measured to be in the general area of 15 in/lbs. In such situations and as a result of relatively low clamping force between the node and the cage, the node can move in the direction perpendicular to the node (side to side) when subjected to shipping shock and vibration.
Consequently, it is desirable to provide to provide a design that provide a solution to the problem of proper mounting of such nodes especially in view of large insertion forces.